Method of effecting a transfer of fluid from a source to a receiver

ABSTRACT

A pre-slit injection site includes a housing with a flow path therethrough. A first end of the housing carries a pre-slit septum. A blunt cannula, usable with the injection site, carries a locking member. When the pre-slit injection site slidably receives the blunt cannula the locking member latches to the injection site forming a mechanically coupled unit.

This is a division of application Ser. No. 147,414 filed Jan. 25, 1988,abandoned.

FIELD OF THE INVENTION

The invention pertains to coupling systems usable to transfer materialsfrom one flow conduit to another. More particularly, the inventionpertains to two-part coupling members with a first part including apre-slit septum and a second part including a blunt cannula. Thepre-slit septum slidably receives the blunt cannula to effect thecoupling.

BACKGROUND OF THE INVENTION

Injection sites usable with pointed cannulae have long been known. Forexample, such sites can be formed with a housing having a fluid flowpath therein. A septum is positioned in the housing closing the fluidflow path.

One injection site usable with a piercing cannula is disclosed in U.S.Pat. No. 4,412,573 to Zdeb entitled "Injection Site." The Zdeb patent isassigned to the assignee of the present invention.

The pointed cannula can be forced through the septum into fluid flowcommunication with the flow path in the housing. Known injection sitesusable with a piercing cannula can be physically damaged by repetitivepiercing caused by the sharp cannula. This damage, known as coring orlaceration, can result in subsequent leakage.

Due to problems associated with infectious agents, personnel using suchpointed cannulae do so with great care. Notwithstanding careful andprudent practice, from time to time, accidents do occur and individualsusing such pointed cannulae jab themselves.

Injection sites usable with a blunt cannula are also known. For example,U.S. Pat. No. 4,197,848 issued to Garrett et al. entitled "ClosedUrinary Irrigation Site" and assigned to the assignee of the presentinvention discloses one such injection site. That injection site is arelatively low pressure device having a relatively thin, molded, sealingmember. The sealing member has an opening therethrough.

A blunt cannulae can be forced through the sealing member placing thecannulae into fluid flow communication with a fluid flow pathway in theinjection site.

Injection sites of the type noted above usable with a blunt cannula havethe advantage that the blunt cannula will not pierce the skin of a user.On the other hand, it is important that the pre-slit injection sitereseal with enough force that fluids do not ooze therefrom and thatairborne particulate matter, bacterial or viral matter do not entertherethrough.

Hence, there continues to be a need for a pre-slit injection site whichcan be used with a variety of solutions and over a range of fluidpressures. Further, there continues to be a need for such a pre-slitinjection site which will reliably reseal even after many insertions ofthe blunt cannula.

Such an injection site should be able to receive a large number ofinsertions of the cannula without displaying reseal failure. Such aninjection site should provide for improved alignment of the cannula oninsertion. Improved alignment will result in less chance of damage tothe injection site after repeated insertions of the cannula. Preferably,the injection site would also be usable with a pointed cannula.Preferably, a pre-slit injection site usable with a blunt cannula willprovide a reasonable level of insertion force such that health carepersonnel will readily be able to insert the blunt cannula, yet thecannula will not easily fall from or drop out of contact with theseptum.

SUMMARY OF THE INVENTION

In accordance with the invention, an easily wipeable injection siteusable with a blunt cannula is provided. The injection site includes ahousing which defines a fluid flow channel therethrough. The housing hasa first and a second end.

A flexible sealing member is carried by the housing for sealing thefirst end. The sealing member has a resealable opening therein. Thesealing member also is formed with a curved exterior peripheral surfacesuch that the blunt cannula can be sealingly inserted through theopening and placed in fluid flow communication with the flow path.Further, the blunt cannula can be removed from the opening with thesealing member then interacting with the housing so as to reseal theopening.

The housing can also be formed with the first end including an annularchannel underlying the sealing member. The sealing member is subjectedto radially directed forces by a tapered surface of the first end of thehousing. These forces tend to reseal the opening in the sealing member.

The sealing member can be a cylindrically shaped rubber member. Thefirst end of the housing can include an interior tapered surface forreceiving the sealing member and for applying the radially directedforces to the sealing member.

A retaining member carried by the first end of the housing can be usedto retain the sealing member within the housing. The retaining membercan be generally U-shaped. Alternately, the retaining member can beformed as a coiled spring.

The retaining member applies axially directed forces to the sealingmember. In one embodiment of the invention, the retaining memberdeflects the sealing member and forms a curved exterior peripheralsurface thereon. The curved exterior peripheral surface is an easilywipeable surface.

The retaining member deflects or distorts the upper and lower peripheraledges slightly as a result of applying axial forces thereto. When theblunt cannula is inserted into the slit in the sealing member, anannular interior peripheral region of the sealing member deforms furtherand fills, at least in part, the annular channel.

Deformation of this annular peripheral region results in an insertionforce in a range of 2.0 to 5 pounds. Preferably, the insertion forcewill have a value of the order of 2.0 pounds.

The resealable opening in the sealing member can extend entirely throughthat member. Alternately, the resealable opening can extend only partwaytherethrough. In this embodiment, the end of the blunt cannula will beused to tear through the remainder of the sealing member.

The sealing member can be formed in two parts. An exterior cylindricalportion can be slit completely. An interior cylindrical unslit portioncan be provided to seal the site until the blunt cannula is insertedtherethrough the first time.

The interior surface of the first end can be formed with the taper in arange on the order of 5 degrees to 20 degrees. Preferably, the interiorsurface will have a taper on the order of 12 degrees. This taperedsurface permits the use of a cylindrically shaped sealing member.

To provide for leak-free insertion, the length of the slit in thesealing member must be less than one-half the circumference of thecannula being inserted therethrough. Hence, the slit length may exceedthe diameter of the cannula being inserted. In addition, the slit lengthmust be great enough, given the elastic limit of the sealing member, toprevent tearing during insertion.

Further in accordance with the invention, a coupling system for couplingfirst and second fluid flow members together is provided. The couplingsystem includes an injection site which is affixed to the first fluidflow member. The injection site includes a housing. The housing has afluid flow path therethrough.

A sealing member is carried by the housing. The sealing member has aresealable opening therein.

An annular retaining member is carried by the housing and cooperateswith the housing to retain the sealing member therein. Radially directedforces are applied to the sealing member by the housing, thereby urgingthe opening into a resealed condition.

A blunt cannula, affixed to second fluid flow member, has a fluid flowpath therethrough. The cannula carries a locking member for lockinglyengaging the housing when the cannula extends through the opening of thesealing member. When so positioned, the two fluid flow members areplaced into fluid flow communication.

The locking member can include a luer-type twist lock fitting.Alternately, the locking member can include slidably engageable memberswhich are responsive to axial movement of the injection site and thecannula toward one another.

Other advantages of a blunt plastic cannula in accordance with theinvention, relative to conventional steel needles include a higher fluidflow rate capacity and a simpler 1-piece plastic design.

Numerous other advantages and features of the present invention willbecome readily apparent from the following detailed description of theinvention and the embodiments thereof, from the claims and from theaccompanying drawings in which the details of the invention are fullyand completely disclosed as a part of this specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view, partly in section, of a prior artpre-slit injection site and an associated blunt cannula;

FIG. 2A is a view in perspective of a catheter positioned in the hand ofa patient with a pre-slit injection site in accordance with the presentinvention positioned adjacent thereto;

FIG. 2B is a perspective view of the catheter of FIG. 2A with a pre-slitinjection site in accordance with the present invention rotatablyaffixed thereto;

FIG. 3 is an enlarged side elevational view in a section of a pre-slitinjection site in accordance with the present invention formed on a bodyhaving a luer twist-lock type connector for coupling to a catheter;

FIG. 4A is an exploded view of a pre-slit injection site, a shieldedblunt cannula and a syringe prior to being coupled together;

FIG. 4B is an enlarged, side elevational view in section of the pre-slitinjection site, the shielded blunt cannula and the syringe of FIG. 4Acoupled together to form a sealed fluid flow system;

FIG. 5A is a view in perspective of a pre-slit injection site prior toengaging a blunt cannula carrying a locking member;

FIG. 5B is an enlarged side elevational view, partly broken away,illustrating the interrelationship between the pre-slit injection siteand the blunt cannula of FIG. 5A;

FIG. 6 is an overall view of a container, an associated solutionadministration set and a pre-slit injection site in accordance with thepresent invention;

FIG. 7 is an enlarged side elevational view, partly broken awayillustrating the relationship between selected elements of FIG. 6;

FIG. 8 is a side elevational view, partly broken away illustrating analternate shielded cannula in accordance with the present invention;

FIG. 9 is a side elevational view, partly in section, of a pre-slitinjection site mounted on a fragment of a solution container;

FIG. 10 is a side elevational view of a fragment of a solution containercarrying, as a single port, a pre-slit injection site;

FIG. 11 is a side elevational view of the injection site and thefragmentary container of FIG. 10 prior to being engaged with a shieldedcannula carried by a syringe;

FIG. 12 is an enlarged side elevational view, partly in section, of acoupling system with a pre-slit injection site partly coupled to a bluntcannula;

FIG. 13 is an enlarged side elevational view, partly in section, of thecoupling system of FIG. 12 subsequent to engagement of the two couplingmembers;

FIG. 14 is a side elevational view, partly broken away, of a spikeconnector carrying a pre-slit injection site in accordance with thepresent invention;

FIG. 15 is an enlarged side elevational view of a Y-connector in sectioncarrying a pre-slit injection site in accordance with the presentinvention;

FIG. 16 is an enlarged fragmentary side elevational view in section of acoupling member carrying a pre-slit injection site where the slitextends only partway through the septum;

FIG. 17 is a perspective view of a burette solution administration setcarrying a pre-slit injection site in accordance with the presentinvention;

FIG. 18 is a view of part of a burette solution administration setcarrying a pre-slit injection site being coupled to a shielded bluntcannula;

FIG. 19 is a step in the method of making a pre-slit injection site inaccordance with the present invention;

FIG. 20 is another step in the method of making a pre-slit injectionsite in accordance with the present invention;

FIG. 21 is an initial phase of a final step in making a pre-slitinjection site in accordance with the present invention;

FIG. 22 is an intermediate phase of the final step in a method of makinga pre-slit injection site in accordance with the present invention;

FIG. 23 is a final phase of the final step in a method of making apre-slit injection site in accordance with the present invention;

FIG. 24 illustrates an initial phase in an alternate step of making apre-slit injection site in accordance with the present invention;

FIG. 25 illustrates a final phase of the alternate step in a method ofmaking an injection site in accordance with the present invention;

FIG. 26 illustrates yet another alternate step in a method of making apre-slit injection site in accordance with the present invention; and

FIG. 27 is an enlarged, fragmentary cross-sectional view of anotherembodiment of an injection site in accordance with the presentinvention; and

FIG. 28 is a cross-sectional view taken generally along the plane 28--28in FIG. 27.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

While this invention is susceptible of embodiment in many differentforms, there are shown in the drawing and will be described herein indetail specific embodiments thereof with the understanding that thepresent disclosure is to be considered as an exemplification of theprinciples of the invention and is not intended to limit the inventionto the specific embodiments illustrated.

A prior art pre-slit injection site 10 and associated blunt cannula 12are illustrated in FIG. 1. The prior art injection site 10 has acylindrical housing 14 with a fluid flow path 16 therethrough. A firstend 18 of the housing 14 is closed with a relatively thin disc-shapedresealable member 20. The member 20 has a resealable opening 22 therein.

The member 20 is a molded septum with an integrally formed skirt 20a.The skirt 20a is oriented generally perpendicular to the portion of theseptum with the opening 22.

The cannula 12 includes a body portion 24 which carries at a first end ahollow, cylindrical, blunt piercing member 26. As the cannula 12 ismoved in a direction 28 toward the first end 18 of the injection site10, the member 26 slidably engages the opening 22. The sealing member 20is then deformed adjacent the opening 22 and the member 26 extends intothe flow path 16. A fluid flow path through the cannula 12 will then bein fluid flow communication with the flow path 16 via the hollowpiercing member 26.

In contradistinction to the prior art pre-slit injection site 10 of FIG.1, FIGS. 2A and 2B illustrate a pre-slit injection site 34 being coupledto a peripheral venous catheter 36. The catheter 36 is shown in fluidflow communication with a vein in a hand H of a patient. The catheter 36carries at a proximal end of catheter housing 38 a luer-type femaletwist lock connector 41.

The pre-slit injection site 34 is formed with a cylindrical housing 40having a first end 42 and a second end 44.

Carried by the housing 40, adjacent the second end 44 is a hollowcylindrical fluid flow member 46. The member 46 slidably engages areceiving member in the housing 38 of the catheter 36, thereby providinga sterile fluid flow coupling as is well known and conventional.

A plurality of internal male luer-type threads 48 is carried by thehousing 40 adjacent the second end 44. The threads 48 will engage theflange member 41 when the injection site 34 is rotated in a direction50. When so coupled together, the catheter 36 and the injection site 40provide a sealed coupling through which fluids may be injected into thevein of the hand H.

FIG. 3 illustrates, in section, further details of the injection site34. A resealable septum 52 is carried by the first end 42 of the housing40. The septum 52 includes first and second spaced apart surfaces 54 and56 respectively. The surface 54 has been forced into a dome-like shapeby annular, U-shaped, swaged end members 58 carried by the first end 42.The dome-like shape of the surface 54 can extend beyond a surface 42a ofthe first end 42. This facilitates cleaning the surface 54.

The septum 52 has a generally cylindrical shape. The septum 52 can beformed of a latex or synthetic rubber material. Alternately, the septumcan be formed of a thermoplastic elastomer. The material used for theseptum 52 should be non-toxic and sterilizable such as by means ofradiation, steam or ethnene oxide.

Because the septum 52 is generally cylindrical in shape, it can bedie-cut from a sheet, cut from an extruded rod or molded. The septum 52can have an exemplary diameter on the order of 0.30 inches. The heightof the septum 52 can be, for example, on the order of 0.125 inches.

The first end 42 is also formed with a tapered interior surface 60 whichterminates in an annular channel 62. The tapered interior surface 60 hasa taper in a range of 5 degrees to 20 degrees. Preferably, the taperwill be on the order of 12 degrees. With the indicated size of the abovenoted exemplary septum 52 and a 12 degree taper, diametric resealingcompression of the septum 52 adjacent the channel 62 is on the order of10%.

The channel 62 is bounded in part by a septum supporting ridge 62a. Thechannel 62 can typically have a depth in a range of 0.050-0.070 inches.

A peripheral surface 64 of the septum 52 slidably engages the taperedinterior surface 60 as the septum 52 slides into the first end 42. Theannular channel 62 which underlies the interior peripheral surface 56 ofthe septum 52 is provided to permit the septum 52 to deform when a bluntcannula is inserted through an opening 66 therein.

The housing 40 is also formed with a fluid flow path 68 such that fluidsinjected via a blunt cannula inserted through the resealable opening 66can flow into the catheter 36 for delivery to hand H of the patient.

The swaged end members 58 apply axial forces to the septum 52 therebycreating the domed exterior peripheral surface 54. The axial forcesapplied by the end members 58 slightly deform the regions 52a and 52b.In contradistinction, the tapered internal surface 60 applies radiallydirected forces to the septum 52, thereby forcing the opening 66 into aresealed condition.

In an alternate embodiment, the surface 52 could be formed as a flat, asopposed to a domed, surface.

Once the injection site 34 is lockingly engaged with the catheter 36, asealed system is formed through which fluids can be infused into thecatheter 36. The resealable septum 52 closes the fluid flow path 68.

FIGS. 4A and 4B illustrate in combination the injection site 34, a bluntshielded cannula 80 and a syringe of a conventional type 82. The syringe82, as is well known, can be formed with a cylindrical hollow end 84which carries a male luer-type twist lock thread 86. A hollow centrallylocated cylindrical fluid flow member 88 is in fluid flow communicationwith an interior region 90 of the syringe 82.

The shielded blunt cannula 80 carries at a first end 92 a female luertwist-lock flange 94. The flange 94 will slidably engage the threads 86of the end 84. Hence, the shielded blunt cannula 80 can be locked to thesyringe 82 forming a closed fluid flow pathway. The shielded cannula 80could alternately be formed fixedly attached to the syringe 82.

The shielded blunt cannula 80 carries a cylindrical hollow protectiveshield 96 which surrounds a centrally located hollow, elongatedcylindrical blunt piercing member 98. The cylindrical blunt piercingmember 98 has a total length on the order of 3 times the thickness ofthe septum 52 in order to ensure complete penetration. The cylindricalblunt piercing member 98 has a diameter on the order of 1/3 the diameterof the septum 52. The shield 96 is desirable and useful for maintainingthe piercing member 98 in an aseptic condition by preventing touchcontamination prior to the shielded cannula 80 engaging the pre-slitseptum 52. Also, the shield helps to align the piercing member with thepre-slit septum.

The cylindrical blunt piercing member 98 can slidably engage thepre-slit septum 52, best illustrated in FIG. 4B, thereby extendingthrough the performed opening 66 therein. As illustrated in FIG. 4B,when the piercing member 98 slidably engages and pierces the septum 52,the region 52a deforms by expanding into and filling, at least in part,the annular channel 62.

The deformation facilitates insertion of the piercing member 98 throughthe slit 66. Subsequent to the piercing member 98 slidably engaging theinjection site 34, the interior region 90 of the syringe 82 is in fluidflow communication with the flow path 68 of the injection site 34 viaflow paths 88a and 99a respectively of the syringe and the bluntpiercing member 98.

In this engagement condition, the septum 52 seals completely around thepiercing member 98. Hence, exterior gases, liquids or airborne matterwill be excluded from the channel 68.

Subsequent to infusing fluid from the syringe 82 into the fluid flowpathway 68, hence into the catheter 36 and the hand H of the patient,the syringe 82 with lockingly engaged shielded cannula 80 can beslidably withdrawn from the injection site 34. Subsequent to thiswithdrawal, the septum 52 reseals the opening 66 therein.

The opening 66 will repeatedly reseal, when the piercing member 98 isremoved, provided that the pressure (in the septum 52 of the opening 66)created by interaction of the septum material properties and compressionsupplied by the housing exceeds the pressure challenge of the fluidcontained within. Blunt cannula do not haphazardly core, lacerate, orotherwise damage the sealing interface 66 as conventional needles do,thereby allowing repeatable resealability. However, septum materialproperties, thickness, and compression allow resealability for a finitenumber of conventional needle insertions. The combination injection site34 and catheter 36 then return to its pre-infusion, sealed condition.

FIGS. 5A and 5B illustrate the pre-slit injection site 34 used incombination with a blunt cannula 80a. The cannula 80a includes piercingmember 98a and manually operable elongated locking members 100a and100b.

Curved end regions 100c of the members 100a and 100b slidably engage thesecond end 44 of the housing 40 when the piercing member 98a of theblunt cannula 80a has been forced through the pre-formed opening 66,best illustrated in FIG. 5B. The embodiment illustrated in FIGS. 5A and5B has the advantage that the infusing cannula 80a cannot accidentallydisengage from the pre-slit septum 34 during the fluid infusion process.It will be understood that while spring-like deflecting members 100a and100b are illustrated in FIGS. 5A and 5B that other forms of lockingmembers are within the spirit and scope of the present invention.

The blunt cannula 80a terminates at a proximal end with female luerfitting 94a. Alternately, a tubing member could be affixed to the hollowbody portion 92a.

FIG. 6 illustrates an alternate pre-slit injection site 34a. A tubingmember 102 can be fixedly attached to the cylindrical hollow fluid flowmember 46. The embodiment 34a of FIG. 6 utilizes the same structure forthe septum 52 including the tapered surface 60 and the underlyingannular channel 62 as does the embodiment 34. The shielded cannula 80can be utilized with the injection site 34a as previously described.

In the event that it is desirable to infuse solution from a container104 with a conventional port 106, a fluid administration set 110 of aconventional variety may be utilized. The set 110 includes a spikeconnector 112 at a first end. The spike connector 112 is designed topierce the port 106 of the container 104. The set 110 can also carry aslidably engageable connector 114 of a known type at a second end. Asillustrated in FIG. 7, the connector 114 can slidably engage the hollowcylindrical member 98 of the shielded cannula 80, thereby placing theinterior fluid of the container 104 into fluid communication with thetubing member 102.

FIG. 8 illustrates yet another alternate 80b to the shielded cannula 80.The piercing member 98b carries a tubing member 118 fixedly attachedthereto. The tubing member 118 could be coupled at a second end to acontainer such as the container 104.

The present pre-slit injection site can be directly affixed to acontainer 120 as illustrated in FIG. 9. The container 120 includes arigid hollow cylindrical access port 122 affixed thereto. The accessport 122 includes a fluid flow channel 124 in fluid flow communicationwith the interior of the container 120. Sealingly affixed to the port122 is a pre-slit injection site 126.

The site 126 includes a cylindrical housing 128 which carries at a firstend 130 a septum 132 with a slit 134 formed therein. The first end 130has been swaged to form an annular U-shaped retaining member 136. Theretaining member 136 in turn forms a domed exterior peripheral surface138 on the septum 132.

The first end 130 also includes a tapered interior force applyingsurface 140 and an annular channel 142 underlying the septum 132. Asdiscussed previously, the channel 142 provides a space into which theseptum 132 can deform when a blunt cannula is forced through theresealable opening 134.

Further, as illustrated in FIG. 9, the injection site 126 can be coveredby a removable cover 146 of a type used with the conventional port 106of the bag 120.

While the bag 120 is illustrated formed with two ports, the conventionalpierceable port 106 and the pre-slit injection site 126, it will beunderstood that as an alternate (FIG. 10), a container 150 could beformed which includes only the pre-slit injection port 126. Theremovable cover 146 could be used in combination with the container 150.

As illustrated in FIG. 11, the pre-slit injection site 126 can beutilized for the purpose of injecting fluid from the syringe 82, coupledto the shielded cannula 80, into the container 150. When so utilized,the blunt piercing member 98 is used to place the interior fluidcontaining region 90 of the syringe into fluid flow communication withthe interior of the container 150.

FIGS. 12 and 13 illustrate a fluid flow coupling system 151 having as afirst element a pre-slit injection site 126a. The site 126a is the sameas the site 126 except for a plurality of exterior threads 153 formed onan exterior peripheral surface 155 of the housing 128a. A second elementof the coupling system 151 is formed as a shielded blunt cannula 157.

The shielded blunt cannula 157 is sealingly affixed to a flexible tubingmember 159 by means of a proximal hollow cylindrical member 161. Themember 161 extends into a hollow cylindrical shield 163 to form a bluntpiercing member 165.

The shield 163 carries, on an interior peripheral surface, a set ofcoupling threads 149a. The threads 149a match the threads 132.

The two connector elements 126a and 157 slidably engage one another whenthe shielded cannula 157 moves in an axial direction 167 toward theinjection site 126a. The blunt piercing member 165 penetrates the septum132a.

The coupling member 157 can then be rotated in a direction 169 such theinterior set of threads 149 carried thereon engages the exterior set ofthreads 153. As a result, the two coupling members 126a and 157 arelockingly engaged together with the insertion member 165 extendingthrough the opening 134a in the septum 132a. Hence, fluids can flow fromthe container 150a via the connector system 126a and 157 through thetubing member 159 to the recipient.

Injection sites of the type described above are also usable inconnection with other fluid flow coupling components. For example, withrespect to FIG. 14, a pre-slit injection site 160 of the type describedabove can be used in combination with a spike connector 162 of aconventional variety. Spike connectors such as the spike connector 162can be used to pierce conventional ports such as the port 106 of thecontainer 104 (FIG. 6). When the spike connector 162 is so used, thepre-slit injection site 160 can then be utilized for the purpose ofcoupling to other fluid administration sets.

The injection site 160 illustrates an alternate form of swaging thefirst end 42c for the purpose of retaining the septum 52c therein. Thefirst end 42c can be swaged so as to form an annularly shaped, spiral,spring-like member 164. The member 164 has a free end 164a which engagesthe exterior dome-shaped peripheral surface 54c of the septum 52c. Thespiral, spring-like swaged member 164 will tend to uncoil, therebycontinuously applying axial force to the septum 52c and maintaining thedomed exterior peripheral surface 54c.

In yet another alternate, FIG. 15 illustrates a pre-slit injection site166 formed in a Y-junction member 168. The Y-junction member 168 isfixedly attached to first and second tubing members 170 and 172respectively.

As an alternate to forming the slit 66 completely through the septum 52,as illustrated in FIG. 16 a slit 66e can be formed only partly throughthe septum 52e. Such a structure has the further advantage that untilused for the first time the septum 52e is completely sealed.

The septum 52 can be formed in two parts. One part can have a slit, suchas the slit 66 extending entirely therethrough. A second part can beformed without a slit. These two parts can be located adjacent oneanother in the first end 42 of the injection site.

The slit 66 may be longer on the top of the septum than the bottom. Thisfeature aids blunt cannula alignment with the slit upon insertion, andaids resealability by minimizing the critical slit sealing interfacearea.

In accordance with the present invention, the slit 66 could have alength with a range on the order of 0.03 to 0.150 inches. Preferably, aslit length in the order of 0.07 inches will be used in combination witha blunt cannula having a diameter on the order of 0.1 inches.

When initially used, the blunt cannula piercing number 98 will be forcedthrough the slit 66a. The lower peripheral surface 56e will then bepunctured, providing access for the blunt cannula piercing number 98into the fluid flow pathway 68e.

Pre-slit injection sites of the type described above can be utilized incombination with burette solution administration sets. One such set 176is illustrated in FIG. 17. The set 176 includes a pre-slit injectionsite 178 of the type described above. The injection site 178 is affixedto an exterior planar surface 180 of the burette 182. A removal cover184 can be used to maintain the injection site 178 in an asepticcondition until blunt cannula 186 or 188 is inserted therethrough.

FIGS. 19-23 discloses a method of making a pre-slit injection site inaccordance with the present invention. In a first step, a housing 200 isprovided. The housing 200 has an interior tapered surface 202 at firstend 200a thereof. The interior peripheral surface terminates in anannular channel 204. A cylindrical septum 206 can be provided adjacentthe end 200a.

In a second step, the septum 206 can be forced into the end 200a of thehousing 200 and slightly deformed by the tapered peripheral surface 202using an axially moving die 210. When positioned by the die 210, thespetum 206 is located adjacent an internal annular ring 212 which boundsthe annular channel 204.

In a third step, a second die 214 can be utilized to swage the end 200ainto spiral-shaped, spring-like members 200b which apply axiallydirected forces against an exterior peripheral surface 206a of theseptum 206. The axially directed forces form the flat surface 206a intoa domed exterior peripheral surface 206b as illustrated in FIG. 23.

Simultaneously, with swaging the end members 200a so as to lock theseptum 206 into the housing 200 and to form the domed exteriorperipheral surface 206b, a knife 216 can be utilized to form a slit inthe septum 206. Alternatively, the slit may be cut by a separate die ina separate step. If the septum 206 is formed as an extrusion, the slitcan be created during the extrusion process. If the septum 206 is formedby stamping from a rubber sheet, the slit can be cut during the stampingprocess. If the septum 206 is formed by compression molding, the slitcan be cut during the trimming process.

In order to extrude the slit into rod, a flat pin extrusion bushing canbe used. A trailing ribbon may be attached to the bushing. The ribbonwould prevent curing material across the slit. The ribbon or wire couldbe placed in the rod core and later stripped out leaving a slit. Aninert substance, such as silicone oil, could be coextruded in the centerof the rod to prevent curing across the slit and provide lubrication anda visible target for cannula insertion.

FIGS. 24 and 25 illustrate alternate swaging steps wherein a die 220moving axially toward the housing 200 swages the end region 200a so asto form an annular U-shaped region 200c and the exterior domedperipheral surface 206c.

The dies 214 or 220 can be formed with various alternate shaped swagingsurfaces 224, as illustrated in FIG. 26, depending on the precise shapeof the end swag which is desired. It will be understood that all suchvariations in the swaging operation are within the spirit and scope ofthe present invention.

The injection site configuration need not be limited to theconfigurations depicted in FIGS. 3-5B, 9, 12-16. Rather, severalconfigurations could be constructed without departing from the scope ofthis invention. Any such configuration would provide a flexible preslitsealing member captured in a housing which provides compression tocreate a seal against pressure and a void region accessible to thesealing member material only when displaced by a blunt cannula piercingmember. One such possible configuration is depicted in FIGS. 27 and 28.

From the foregoing, it will be observed that numerous variations andmodifications may be effected without departing from the spirit andscope of the novel concept of the invention. It is to be understood thatno limitation with respect to the specifice apparatus illustrated hereinis intended or should be inferred. It is, of course, intended to coverby the appended claims all such modifications as fall within the scopeof the claims.

What is claimed is:
 1. A method of effecting a transfer of fluid from asource to a receiver using a resealable injection site with a per-slitseptum and a blunt cannula comprising the steps of:applying axiallydirected forces to the septum to form an outwardly, easily wipableexterior peripheral surface; applying radially directed forces to theseptum to reseal the slit therein; inserting the blunt cannula into andthrough the slit in the septum, thereby counteracting, at least in part,the radially directed resealing forces; and infusing fluid from thesource through the blunt cannula to the injection site and then to thereceiver.
 2. A method of effecting a transfer of fluid from a source toa receiver using a resealable injection site with a per-slit septum anda blunt cannula comprising the steps of:applying axially directed forcesto the septum to form an outwardly, wipable exterior peripheral surface;applying radially directed forces to the septum to reseal the slittherein; inserting the blunt cannula into and through the slit in theseptum, thereby counteracting, at least in part, the radially directedresealing forces; and transferring fluid from the source through thecoupled cannula and injection site, then to the receiver.
 3. A method ofeffecting a transfer of fluid from a source to a receiver using aresealable injection site with a preslit septum and blunt cannulacomprising the steps of:applying axially directed forces to the septumto form a curved, easily wipable exterior peripheral surface; applyingsufficient radially directed forces to the septum to reseal the slittherein perventing fluid flow therethrough; inserting the blunt cannulainto and through the slit in the septum and into an interior area,thereby conuteracting, at least in part, the radially directed resealingforces; transferring fluid from the source through the coupled cannulaand injection site, then to the receiver; and removing the cannula fromthe injection site and allowing the septum alone to prevent fluid flowfrom said interior area out of the septum.